Classic/Antique Car Repair: St300 transmission, vacuum modulator, transmission case

Question
Brad: I have a Super Turbine 300 2 speed automatic in my 1950 Willys, with a Spicer transfer case hooked up. I bought them together as a unit, and both work. The question involves a leak that I am having, even sitting still not running, that seems to be coming from the Vacuum Modulator.  I can't see in there really well, and don't want to pull the tranny.  Any ideas about what to check for; fix, etc.  I really appreciate it. R.J.

Answer
There is supposed to be a gasket between the modulator and the transmission case and if it missing or damaged can cause a leak. If the modulator has a leak in the diaphram it could leak but would also cause delayed up shift and transmission fluid being sucked into the  engine when running. If that happens the exhaust of the car smokes blue.
Brad